A conventional DIP (dual in-line package) switch is shown in FIGS. 11, 12(A) and 12(B), where the switch comprises movable terminals 1, fixed terminals 2, a wafer 3, a casing 4 mounted to the wafer 3, and levers 5 pivotally mounted to the casing 4 by means of a shaft 5d. Each movable terminal 1 consists of a portion 1a to which solder is to be applied, a portion 1b for producing a clicking operation, and a contact portion 1c. Each fixed terminal 2 consists of a portion 2a to which solder is applied and a contact portion 2b. After molding the wafer 3, the terminals 1 and 2 are mounted in the assembly and tightened during assembly operation. Adhesive is then applied to the terminals 1 and 2 and dried to provide intermediate parts. Each lever 5 has an operation portion 5a and actuating portions 5b and 5c.
The condition in which the levers 5 are not actuated is shown in FIG. 12(A). Under this condition, if the operation portion 5a of each lever 5 is depressed, the actuating portion 5b rides over the portion 1b of the corresponding movable contact 1 and pushes the contact portion 1c. Then, the contact portion 1c of the movable terminal is made contact with the contact portion 2b of the fixed terminal 2 , and the lever 5 is maintained depressed in that position, as shown in FIG. 12(B).
Under this condition, if the operation portion 5a of each lever 5 is pushed upward, the actuating portion 5b is caused to ride over the portion 1b of the movable terminal 1 by means of this upward force plus the resilience of the terminal 1 itself. Finally, it is restored to the condition shown in FIG. 12(A), where each two corresponding contact portions are not in contact with each other.
Switches as constructed in this way might be cleansed for each printed circuit board after being installed on such boards. Therefore, tape is stuck to windows 4a of the casing 4 through which the operation portions 5a of the levers 5 protrude. Unfortunately, in this prior art switch, adhesive used to bond the terminals 1 and 2 and adhesive used to bond the casing 4 to the wafer 3 sometimes flow onto the portions 1a and 2a to be later soldered, making the soldering operation unfeasible. In bonding the terminals 1 and 2 to the wafer 3, these terminals 1 and 2 tend to tilt. If tilted, contact may not be made at the intended position. Further, the contact pressure may deviate from the intended value and vary among finished products.
Another conventional DIP (dual in-line package) switch is shown in FIGS. 13, 14(A), and 14(B). This switch is comprised of movable terminals 6, fixed terminals 7, a first wafer 8a, a second wafer 8b, a casing 9 mounted on the wafers 8a and 8b, levers 11, and actuating portions 10 formed integrally with the respective levers 11. Each movable contact 6 is composed of portion 6a to which solder is to be applied and a contact portion 6b for producing a clicking operation when a contact is made. Each fixed terminal 7 has a portion 7a to which solder is to be applied and a contact portion 7b. The movable terminals 6 are inserted in the molded wafer 8a. Similarly, the fixed terminals 7 are incorporated in the molded second wafer 8b. The wafer 8a is provided with a protrusion 8a.sub.1 that is fitted into a recess 8b.sub.1 in the wafer 8b, and both wafers are bonded together with adhesive. The levers 11 has operation portions 11a which protrude outwardly through windows 9a in the casing 9. When the switch is cleansed, tape is stuck to the windows 9a in the same manner as the foregoing switch.
FIG. 14(A) shows the condition in which the contact portion 6b in each movable terminal 6 is fitted in a recess 10a formed in each actuating portion 10 and in which the actuating portions 10 urge the respective movable terminals 6 downwardly, disengaging the terminals 6 and 7 from each other. Under this condition, if the operating portions of the levers 11 are moved to the left, the contact portions 6 disengage from the respective recesses 10a in the actuating portions 10. Then, the movable terminals 6 are returned upward by their own resilience, so that the contact portions 6b of the movable terminals 6 come into engagement with the respective contact portions 7b of the fixed terminals 7.
In the prior art switch described just above, adhesive used to bond together the fitted wafers 8a and 8b and adhesive used to bond the wafers 8a and 8b to the casing 9 may flow onto the portions 6a and 7a to be soldered later, thereby making the soldering operation impossible. Also, an error arises inevitably in fitting the wafer 8a into the wafer 8b. Thus, contacts are made in incorrect positions, and the contact pressure deviates from the intended value. In this way, difficulties are encountered in the same fashion as in the above-mentioned conventional switch.